Startup and transport characteristics of oscillating heat pipe using ionic liquids
Startup and transport characteristics of oscillating heat pipe using ionic liquids
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DOI：
10.1016/j.icheatmasstransfer.2018.03.004
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发表时间：
2018-05
影响因子：
7
通讯作者：
Qianqing Liang;Tingting Hao;Kai Wang;Xuehu Ma;Z. Lan;Yaxiong Wang
中科院分区：
文献类型：
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作者：
Qianqing Liang;Tingting Hao;Kai Wang;Xuehu Ma;Z. Lan;Yaxiong Wang
研究了离子液体对四圈铜振荡热管启动、运行和热性能的影响。利用高速摄像机对不同热输入下的液塞振荡特性和流型进行了实验研究。实验结果表明，随着离子液体质量分数的增加，OHP的启动功率和启动温度分别降低了29 W和11 °C，这不仅有利于OHP的快速启动，而且有效地避免了“干涸”问题。当离子液体的质量分数为0.67%时，离子液体-水基OHP的振幅和速度与水基OHP基本相同。当离子液体添加量分别为19.1%和44.4%（质量分数）时，振荡液塞呈现出高频小振幅的特性。当离子液体的质量分数较低时，离子液体-水基OHP的传热性能与现有的水基OHP几乎相同。然而，IL-水基OHP的传热性能在较高的热输入（>220 W）下显示出10%的略微降低，这通常不影响OHP的总体热性能和操作稳定性。建立了修正的Kutateladze数（Ku）关联式，考虑离子液体添加的影响，该关联式在填充率约为65%时，基本上可以预测垂直闭环OHP的热性能，偏差约为±10%。
This paper attempted to investigate the effects of ionic liquids (ILs) addition on the startup, operation and thermal performance of a closed loop copper oscillating heat pipe (OHP, four turns). The liquid slug oscillation characteristics and flow pattern of the OHP with various heat input were also experimentally examined utilizing high-speed camera. The experimental results showed that for higher ILs mass fractions, the OHP behaved a lower startup power (decrease of 29 W) and startup temperature (decrease of 11 °C), which are favorable of not only facilitating a faster startup of the OHP but also effectively avoiding the “dry-out” problem. When the mass fraction of ILs was 0.67%, the ILs-water based OHP substantially had the same amplitude and the velocity as water-based OHP. When the ILs addition was respectively 19.1% and 44.4% (mass fraction), the oscillation liquid slug displayed a high frequency and small amplitude characteristics. In case of a low mass fraction of ILs, ILs-water based OHP nearly perform the same heat transfer performance as the water based OHP presented. However, the heat transfer performance of the ILs-water based OHP showed a slight decrease of 10% at higher heat input (>220 W), which in general did not affect the overall thermal performance and operational stability of the OHP. A modified correlation of Kutateladze number (Ku) was established and could basically predict the thermal performance within approximately ±10% deviation in the vertical closed loop OHP at a filling ratio around 65% considering the effects of ILs addition.